Tìm số hữu tỉ x, biết rằng : (2x - 1)^6 = (2x - 1)^8

Đáp án:

`(2x-1)^6=(2x-1)^8`

`<=>(2x-1)^8-(2x-1)^6=0`

`<=>(2x-1)^6[(2x-1)^2-1]=0`

`<=>` \(\left[ \begin{array}{l}(2x-1)^6=0\\(2x-1)^2=1\end{array} \right.\) 

`<=>` \(\left[ \begin{array}{l}2x-1=0\\2x-1=1\\2x-1=-1\end{array} \right.\) 

`<=>` \(\left[ \begin{array}{l}2x=1\\2x=2\\2x=0\end{array} \right.\) 

`<=>` \(\left[ \begin{array}{l}x=\dfrac12\\x=1\\x=0\end{array} \right.\) 

Vậy `x=0,x=1` hoặc `x=1/2.`